Gas compressor



M. covms GAS COMPRESSOR July 4, 1950 2 Sheets-Sheet 1 Filed June 14,1946 n n n INVENTOR. MEYER COVINJ MudzLct a \iwzwfwova ATTORNEYS y 9 M.CQVINS 2,514,223

GAS COMPRESSOR Filed June 14, 1946 2 She ts-Sheet 2 ll Illlll Illllllllll IN V EN TOR.

' M5 YER Comm/s lax 42mm a M ATTORNEYS III Patented July 4, 1950 UNITEDSTATES ENT OFFICE 1 Claim. 1

This invention relates to a compressor for compressing gases in anefiicient and economical manner.

It is an object of this invention to provide a compressor simple inconstruction in which the cylinder comprises a single piece cylindricalportion closed at each end by a head. Such a construction isadvantageous, of considerable importance and is only possible by usingmy invention in which I provide a two-piece crank comprising a crankportion and a shaft portion and wherein the shaft portion is attachedinto the crank portion. Heretofore, compressors of this type have notbeen marketed because of the expensive design which resulted in the useof a single-piece crank necessitating a two-piece cylinder. A two-piececylinder is expensive in design and construction and is more difficultto manufacture and maintain in tight condition during operation. Asinglepiece cylinder is made possible by using a twopiece crank as Idisclose herein. It is for this reason that for the first time acompressor of this type is a commercial reality.

It is another object of this invention to obtain good lubrication whileat the same time preventing excess lubricating oil being discharged withthe compressed gases. I, therefore, provide a novel lubrication systemin which the lubricating oil is introduced along the shaft or thecrankshaft and the rotation of the shaft works the lubricant into thecylinder. Any excess lubricant is then pumped out of cylinder by meansof the piston action back to the lubricating source of supply. A minimumbut sufficient amount of lubricant within the cylinder is therebymaintained. Lubrication of compressors has always been a difficultproblem to solve. I have solved this problem by my system oflubrication.

It is a further object of this invention to provide a novel arrangementin the construction whereby an interconnected, double -headed and doubleacting piston is actuated by a two-piece half crank.

Still another object of this invention is to provide an improvedarrangement of the inlet and outlet valves which result in a moreefiicient compressor and which is necessary for compressing gases whichare more difficult to pump efficiently than liquids.

It is also an object of the invention to provide a small compactcompressor of large capacity which is economic to build and to operate.

A further object of the invention is to provide an arrangement of theactuating crank so as to take as little space as possible leaving moreroom for the piston thereby increasing the efiiciency several hundredper cent over other previous compressors of similar size.

Generally, my compressor comprises a cylinder constructed of asinglepiece cylindrical portion closed at each end by a head, a double headedinterconnected piston arranged to reciprocate in the cylinder, saidpiston having a slot in the center thereof with its longitudinaldimension at right angles to both the direction of reciprocation of thepiston and to the axis of a crank, said crank comprising a. shaftportion and a crank portion, said shaft portion j ournalled in a bearingextending outwardly from a cylinder, said crank portion operativelyassociated in said slot for reciprocating the piston when the crank isturned.

The lubrication system comprises a lubricant source, means forintroducing the lubricant along the shaft portion of the crank wherebythe rotation of the shaft works the lubricant into the cylinder and aconnection means for returning gases and excess lubricant back to thelubricant source and means associated with the lubricant sourceforseparating said gases, also returned with the lubricant, from thelubricant.

My compressor solves many problems involved in the compression of gaseswhich are not found in the pumping of liquids. The problems are moredifiicult and not as easily solved. It is more difficult to haveefiicient tolerance between the piston and the walls of the cylinder andyet prevent excess leakage. It is more difiicult to lubricate and caremust be taken to have proper inlet and outlet valves for emcientoperation which is not so critical for a liquid pump.

The compressor in the present invention has many uses. One of the mostimportant uses of my compressor is as a tractor pump wherein thecrankshaft of the pump is attached to the power takeoff of the motor andused as an air compressor. It can also be attached to trucks andautomobiles as a tire pump. It may also be used as an air compressor infilling stations and the like. The compressor is compact and efiicientso that it can be used as a portable compressor Wherever an aircompressor is desired. The compressor may also be used as a source, ofcompressed air in spray guns, for spraying insects, fruit trees, paintand the like.

One of the big advantages of my compressor is that low friction losspermits the compressor to be driven by pulley and belt wherein previouscompressors used for the purposes set forth above the high frictionlosses in such compressors necessitated a more positive drive such as achain.

Other advantages, objects and uses of my compressor will become apparentby referring to the drawings in which Figure 1 is a side elevationpartly in cross section showing the arrangement 0f the piston in thecylinder. The storage tank used in connection with the compressor isalso shown.

Figure 2 is a perspective view of the piston.

Figure 3 is an end View of the compressor along: L5

the lines 33 of Figure 1.

Figure 4 is a sectional view taken in the -direc-- tion of the arrowsalong the line 44 of Figural. Figure 5 is a perspective view partly incross section of the cylinder, piston andcrankarrangement.

Figure 6 is a more detailed view of the lubricant source means.

Figure 7 is a cap provided as shown in Figure 6 for permitting air toescape when the excess lubricant is returned to thelubricantsource-means.

Referring to the drawings, a single piece straight walled cylinder Iisprovided; Around the cylinder are a plurality of fins 2 which'are animportant feature in my invention to provide portion thereof which is atright angles to the direction of reciprocation.

A support 8 is provided to-which are-rigidly attached the end supportmembers 9. The end support members 9 also serv as the heads for thesingle piece cylinder I. cylinder heads Q'are held in place tightlyagainst the ends of cylinder I by means of the bolts II) which extendoutside of the cylinder from one end support 9 to the other. Intakevalves II of the tappet type are provided at each end of the cylinderhead 9. Outlet valves 'of the ball and spring check type I2 are providedwhich allow the compressed air to pass through the discharge lines I3into the storage tank I4; Apressure gauge I5 is ,providedjand anout-letline I6 is provided for connection to a device or apparatus whichrequires compressed gas.

One of the main features of my device is the two-piece crank II which isbest shown in Figures 4 and 5. The two-piece crank I'I hasa shaftportion I8 and a crankvportion I9. The shaft portionls is screwed intothe crank "portion I9 at point 20. A pulley wheel 21 is keyed to theshaft portion I8 by means of screw .32 and the slot 33. Thecrank portionI9 is adapted and ar- 5 ranged to rotate in the slot 1 of the pistonthereby pro-yiding the means fonreciprocating the piston ,3 when thepulley wheel 2I is rotated. The shaft portion I8 is journalled in asleeve bearing 22 which extends outwardly from the cylinder I as shown.A helical groove 23 extends circumferentially around the interior-"ofthe sleeve bearing 22 for the reason as will be hereinafter set forth inconnection with the;'lubrication system. Lubrication of my device isobtained as follows:

The-end supports or 4.5

Lubricant source means 24 is provided and is screwed into a threaded tap25. A lever 26 is provided which serves as a hand operated lever forstarting the flow of lubricant into the system. Lubricant is introducedthrough the tap 25 and into the spaced grooves 23 causing the lubricantto work along the entire length of the shaft portion I-8 therebyproviding lubrication for the crank. The rotation of the crankshaftforces the lubricant along the shaft I8 into the cylinder because of thehelical groove 23 and the lubricant enters the cylinder and provideslubrication for the piston. However, it is essential that excesslubrication does not remain in between the piston heads 4 and 5 duringreciprocation of the piston because some of the lubricant is bound towork out through the discharge valves I2. Therefore, a connection 26 inthe bottom of the cylinder I is provided and the reciprocation of thepiston ,forces the excess lubricant as Well as some compressed gasthrough the connection 26, th line 21 back into the lubricant source 24.The lubricant source 24 has a separating chamber 25. In chamber 25 thecompressed gas, so returned along with the excess lubricant, isseparated from the lubricant and the gas is withdrawn through the cap-28provided with an opening 29 which connectswith the. interior of theseparating chamber 25 and the atmosphere. Thus I have provided arecycling system for lubrication of my compressor which providessufiicient lubrication without permitting excess lubricant to accumulatein the cylinder which would result in the discharge of the excesslubricant through the exhaust valves.

The intake valves II work in the exhaust port 30 in the heads 9. Toprevent foreign matter from entering the cylinder, screens 3I areprovided. The pulley wheel 2| may be driven by means of a belt and anysuitable source of power may be used.

My compressor may be constructed of any suitablemetal to accomplish thepurposes set forth herein and the type of metal selected forms no partof my invention.

I claim as my invention:

In a compressor the combination of a horizontal cylinder, said cylindercomprising a, single piece cylindrical portion closed at each end by avertical head, a double headed interconnected piston adapted andarranged to reciprocate in the cylinder and having a slot in the centerthereof with its longitudinal dimensions at right angle to the directionof reciprocation, a half crank adapted and arranged for reciprocatingsaid piston in said cylinder comprising a shaft portion and a crankportion, said crank portion adapted and arranged and operativelyassociated in said slot in such a. manner as to cause reciprocation ofthe piston when the crank is turned, the shaft portion of said crankjournalled in a sleeve bearing extendout outwardly from said cylinder,means for turning the shaft portion of said crank, and means forlubricating said crank and said piston comprising a lubricating sourcemeans, a plurality of spaced grooves within said bearing and extendingcircumferentially around the interior of said bearing, means forintroducing a lubricant from said source through said bearing into saidshaft portion whereby the rotation of said shaft portion works thelubricant along said shaft portion toward the interior of the cylinderthereby lubrieating the interior of the cylinder, and means forreturning the excess lubricant in the bottom of said cylinder to thelubricating source comprising a connection fronrthe bottom of thecylinder to the lubricating source, whereby the piston forces compressedgas and said excess lubricant through said connection, and means forseparating said compressed gas from said excess lubricant in thelubricating source means.

MEYER COVINS.

REFERENCES CITED UNITED STATES PATENTS Number The following referencesare of record in the 19 Number file of this patent:

Name Date Bailey Oct. 11, 1898 Hanna Nov. 8, 1910 Smith, et a1 Dec. 6,1932 Mantle Apr. 21, 1942 Hewitt, et a1 Mar. 11, 1947 FOREIGN PATENTSCountry Date Switzerland Mar. 14, 1917

